Prediction of magnetic moment collapse in ZrFe₂ under hydrostatic pressure

Abstract

Electronic structure and magnetic properties of ZrFe 2 with a cubic Laves phase are investigated by calculations based on the density functional theory. The total magnetic moment (m) of 3.14 µ B per formula unit (f.u.) is obtained at the experimental lattice constant (7.06 Å), which is larger than 3.06 µ B /f.u. obtained at the theoretical equilibrium lattice constant (6.85 Å). The localized 3d magnetic moment is in negative diffusive sp background moment. We predict a two-step magnetic collapse under pressure: one is from 3.06 µ B /f.u. to 1.26 µ B /f.u. at about 3.6 GPa, and the other is from 0.5 µ B /f.u. to nonmagnetic state at about 15 GPa. We understand this process by the changes of density of states. The magnetic moment decreases under the pressure in the vicinity of the experimental lattice constant with d ln m/dp = −0.038 GPa −1 . The spontaneous volume magnetostriction is 0.015. We suggest that the Invar effect of this alloy may be understood when considering the magnetic moment variation according to the Weiss 2γ-model.

Curie temperature study of ${{\rm Y(Fe_{1-\it x}} {\rm {Co}_{\it x})_2}}$ and ${{\rm Zr(Fe_{1-\it x}} {\rm {Co}_{\it x})_2}}$ systems using mean field theory and Monte Carlo method

“…Furthermore, YCo 2 alloys with rare-earth elements R 1−x Y x Co 2 (R = Er, Gd) were investigated as magnetocaloric materials for application in magnetic refrigerators [8,9], similar like Er 1−x Zr x Fe 2 alloys [10]. The above efforts are supplemented by a number of theoretical studies of mechanical [11], electronic [12], and magn etic properties [13,14] concerning ZrFe 2 , YCo 2 , and ZrCo 2 compounds. The binary XFe 2 and XCo 2 phases (including X = Y, Zr) have been also investigated theoretically from a permanent magnets perspective [15].…”

Influence of the critical Fe atomic volume on the magnetism of Fe-rich metallic glasses evidenced by pressure-dependent measurements

“…This discrepancy might be associated with the increasing deviation of the matrix from an ideal FM one upon decreasing Zr content due to cluster formation. In a very recent paper [82], electronic structure and magnetic properties for ZrFe 2 with a cubic Laves phase were calculated based on the density functional theory. According to the calculations, the magnetic moment (m) decreases under pressure in the vicinity of the experimental lattice constant with dlnm/dp = −0.038 GPa −1 .…”